Fix resolution of diagrams in figure 4 and figure 5

[j-aux]

There is a problem in the resolution of the diagrams (the original files are fine but when its put into the paper, it looks blurry/pixelated

Suggestion to address this -

• Either we upload a jpg of the entire diagram to get better resolution of the figuree or
• figure out how to improve the resolution

[j-aux]

Same probleem in figure S2, S3 and S4 (secondary structures)

[ewallace]

I did not fix this in the pull request #178 because I didn't know how and I ran out of time.

I have 3 suggestions:

• adjust the call to ggdraw to change the resolution when loading svg
• adjust the call to ggsave to change the resolution when saving, possibly through fig_dpi paramter in shared_figure_formatting.R
• load the file in a different format, possibly pdf?

To this stack overflow issue has some ideas. https://stackoverflow.com/questions/50026862/the-draw-image-function-from-cowplot-results-in-blurred-pdfs